IPFS can’t fully circumvent censorship when IP blocking is involved. However, imagine each person has their own IP. Alice has a file to share. Boris downloads file from Alice. Charlie wants the file, but can’t access Alice’s IP, Charlie can also access the file via Boris. Without (hypothetically) having to configure anything special.
Traditional internet addresses such as www (dot) sharing (dot) com/fileA will point to the server that the DNS system says is at “www (dot) sharing (dot) com” and within that server “fileA” (assuming no custom web server that does special things with the address information). IP censorship can just block the IP that “www.sharing.com” directs to, thus circumventing access to the server. With IPFS, you put in a file hash instead of an address, (for simplicity) let’s say you want to access the file at hash “sharingFileA” (name simplified for simplicity), you don’t try connecting to the server at sharing.com you ask the network of any IPFS nodes you can connect to if they have the file “sharingFileA” or if they know of a node that does. This partially circumvents censorship because the IP of everyone who has the file would need to be blocked. It’s not completely unblockable though, just harder.